The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
Juan Cacho - One of the best experts on this subject based on the ideXlab platform.
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Behaviour of several solid adsorbents for sampling tetraalkyllead compounds in air
Microchimica Acta, 1994Co-Authors: Cristina Nerin, Bego∼na Pons, Mikel Martinez, Juan CachoAbstract:The behaviour of various solid adsorbents for collecting tetraalkyllead compounds has been studied. A synthetic atmosphere containing a known concentration of tetraethyllead was produced and the tetraethyllead compound was trapped in a glass tube containing the solid adsorbent. The trapped compound was extracted with hexane in an ultrasonic bath, and the resulting solution was analysed by GC-MS. Porapak and Tenax, with retention efficiencies of 92 and 96%, respectively, were shown to be the more efficient at trapping this alkyllead compound than Chromosorb, active charcoal, Amberlites and polyurethane foam. The behaviour of both Porapak and Tenax for trapping other tetraalkyllead compounds in the presence of gasoline vapour was also studied.
Cristina Nerin - One of the best experts on this subject based on the ideXlab platform.
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Behaviour of several solid adsorbents for sampling tetraalkyllead compounds in air
Microchimica Acta, 1994Co-Authors: Cristina Nerin, Bego∼na Pons, Mikel Martinez, Juan CachoAbstract:The behaviour of various solid adsorbents for collecting tetraalkyllead compounds has been studied. A synthetic atmosphere containing a known concentration of tetraethyllead was produced and the tetraethyllead compound was trapped in a glass tube containing the solid adsorbent. The trapped compound was extracted with hexane in an ultrasonic bath, and the resulting solution was analysed by GC-MS. Porapak and Tenax, with retention efficiencies of 92 and 96%, respectively, were shown to be the more efficient at trapping this alkyllead compound than Chromosorb, active charcoal, Amberlites and polyurethane foam. The behaviour of both Porapak and Tenax for trapping other tetraalkyllead compounds in the presence of gasoline vapour was also studied.
Tyge Greibrokk - One of the best experts on this subject based on the ideXlab platform.
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Packed capillary high-temperature liquid chromatography coupled to inductively coupled plasma mass spectrometry
Journal of Chromatography A, 1999Co-Authors: Roger Trones, Anders Tangen, Walter Lund, Tyge GreibrokkAbstract:The applicability of inductively coupled plasma mass spectrometry (ICP-MS) as a detector for high-temperature liquid chromatography with packed capillary columns has been studied. A laboratory-made micro concentric nebulizer was utilized as a interface for the coupling of the two instruments. The repeatability of peak height and area at the investigated column temperatures (75–150°C) was good, with relative standard deviation less than 1.5% (n=3). The limit of detection (LOD) for tetraethyl- and Tetramethyllead was found to be 5 pg as Pb (S/N=3), and for tetraethyltin 9 pg as Sn (S/N=3). The effect of temperature ramping on the baseline was investigated, and no limitations regarding range or rate of temperature increase upon the ICP-MS response were found for the mobile phases used.
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microconcentric nebulizer for the coupling of micro liquid chromatography and capillary zone electrophoresis with inductively coupled plasma mass spectrometry
Journal of Analytical Atomic Spectrometry, 1997Co-Authors: Anders Tangen, Roger Trones, Tyge Greibrokk, Walter LundAbstract:A concentric nebulizer designed to deliver less than 10 µl min -1 directly into an ICP-MS system is described. The influence of the liquid flow rate, the nebulizer gas flow rate and the distance from the nebulizer tip to the plasma was evaluated with regard to sensitivity and precision. The nebulizer was tested at liquid flow rates of 3–7 µl min -1 . Samples of Tetramethyllead and tetraethyllead dissolved in dimethylformamide were used for the evaluation of the nebulizer. The detection limit for Pb ( m =208) with a direct injection system was found to be 0.3 pg (S/N=3) or 5 µg l -1 , based on an injection volume of 60 nl, a liquid flow rate of 5 µl min -1 and a dwell time of 10 ms. The precision was found to be 1.9% ( n =10) based on peak area measurements. The responses of Tetramethyllead and tetraethyllead were not significantly different ( p =0.05). The time needed for one determination was less than 15 s, owing to the quick rinse out of the nebulizer. The nebulizer can be used as part of a direct injection instrumental set-up. An application of the nebulizer to the coupling of packed capillary liquid chromatography with ICP-MS detection is demonstrated.
Robert J Silbey - One of the best experts on this subject based on the ideXlab platform.
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synthesis of doped zns nanoclusters within block copolymer nanoreactors
Chemistry of Materials, 1996Co-Authors: Ravi S Kane, Robert E Cohen, Robert J SilbeyAbstract:We have demonstrated the synthesis of PbS nanoclusters within the microphase-separated films of diblock copolymers containing carboxylic acid units on one of the blocks. Lead was selectively sequestered into the acid containing domains by treating the polymer films with tetraethyllead, and PbS was formed by subsequently treating the films with H2S. The PbS nanoclusters were characterized by X-ray diffraction, X-ray fluorescence, electron microscopy, and UV−vis spectroscopy. The cluster size could be controlled by varying processing parameters such as temperature, the presence of coordinating bases, and the H2S exposure time. Increasing the size of the nanoreactors increased the cluster size. The universal cluster synthesis scheme enabled multiple passes through the process, which were used to increase the cluster size and which could in principle be used to passivate the surface of the PbS cluster or to produce mixed semiconductor clusters.
Bego∼na Pons - One of the best experts on this subject based on the ideXlab platform.
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Behaviour of several solid adsorbents for sampling tetraalkyllead compounds in air
Microchimica Acta, 1994Co-Authors: Cristina Nerin, Bego∼na Pons, Mikel Martinez, Juan CachoAbstract:The behaviour of various solid adsorbents for collecting tetraalkyllead compounds has been studied. A synthetic atmosphere containing a known concentration of tetraethyllead was produced and the tetraethyllead compound was trapped in a glass tube containing the solid adsorbent. The trapped compound was extracted with hexane in an ultrasonic bath, and the resulting solution was analysed by GC-MS. Porapak and Tenax, with retention efficiencies of 92 and 96%, respectively, were shown to be the more efficient at trapping this alkyllead compound than Chromosorb, active charcoal, Amberlites and polyurethane foam. The behaviour of both Porapak and Tenax for trapping other tetraalkyllead compounds in the presence of gasoline vapour was also studied.